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    <center>Scilab Function</center>
    <div align="right">Last update : April 1993</div>
    <p>
      <b>xarrows</b> -  draw a set of arrows</p>
    <h3>
      <font color="blue">Calling Sequence</font>
    </h3>
    <dl>
      <dd>
        <tt>xarrows(nx,ny,[arsize,style])  </tt>
      </dd>
    </dl>
    <h3>
      <font color="blue">Parameters</font>
    </h3>
    <ul>
      <li>
        <tt>
          <b>nx,ny</b>
        </tt>: real vectors or matrices of same size.</li>
      <li>
        <tt>
          <b>arsize</b>
        </tt>: real scalar, size of the arrow head. The default value can be obtained  by setting arsize to -1.</li>
      <li>
        <tt>
          <b>style</b>
        </tt>: matrix or scalar. If <tt>
          <b>style</b>
        </tt> is a positive scalar  it gives the color to use for all arrows. If it is a negative scalar  then the current color is used. If it is a vector <tt>
          <b>style(i)</b>
        </tt> gives the color to use for arrow <tt>
          <b>i</b>
        </tt>.</li>
    </ul>
    <h3>
      <font color="blue">Description</font>
    </h3>
    <p>
      <tt>
        <b>xarrows</b>
      </tt> draws a set of arrows given by <tt>
        <b>nx</b>
      </tt> and <tt>
        <b>ny</b>
      </tt>.
    If <tt>
        <b>nx</b>
      </tt> and <tt>
        <b>ny</b>
      </tt> are vectors,
    the ith arrow is defined by
    <tt>
        <b>(nx(i),ny(i))--&gt;(nx(i+1),ny(i+1))</b>
      </tt>.
    If <tt>
        <b>nx</b>
      </tt> and <tt>
        <b>ny</b>
      </tt> are matrices:</p>
    <pre>

nx=[xi_1 x1_2 ...; xf_1 xf_2 ...]
ny=[yi_1 y1_2 ...; yf_1 yf_2 ...]
   
    </pre>
    <p>
    the <tt>
        <b>k</b>
      </tt> th arrow is defined by <tt>
        <b>(xi_k,yi_k)--&gt;(xf_k,yf_k)</b>
      </tt>.</p>
    <p>
      <tt>
        <b>xarrows</b>
      </tt> uses the current graphics scale 
    which can be set by calling a high level drawing function such as <tt>
        <b>plot2d</b>
      </tt>.</p>
    <h3>
      <font color="blue">Examples</font>
    </h3>
    <pre>

x=2*%pi*(0:9)/8;
x1=[sin(x);9*sin(x)];
y1=[cos(x);9*cos(x)];
plot2d([-10,10],[-10,10],[-1,-1],"022")
xset("clipgrf")
xarrows(x1,y1,1,1:10)
xset("clipoff")
 
  </pre>
    <h3>
      <font color="blue">Author</font>
    </h3>
    <p>J.Ph.C.  </p>
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